President Harry Truman

HARRY TRUMAN was vice president under FRANKLIN D. ROOSEVELT when FDR was elected to his fourth term in 1944. During Roosevelt's first and second terms, his vice president was John Nance Garner of Texas. For his third term, in the election of 1940, Roosevelt chose as vice president Henry A. Wallace of Iowa. In the election of 1944, however, the Democrats picked Harry Truman, who at the time was a U.S. senator from Missouri.  Roosevelt died suddenly on April 12, 1945, and Truman was sworn in as president. As vice president, Truman had been unaware of the work on the atomic bomb, yet within four months he was directing the military use of nuclear weapons for the first time in human history. Truman won reelection by a hair in 1948 and served until January 20, 1953.